Abstract:

There are limitations in utility tunnel construction by traditional methods such as cutandcover method, mining method, shield tunneling method and pipejacking method. In this paper, innovative Ushaped shield mechanized construction methods are put forward according to the characteristics of domestic utility tunnel construction environment, by analyzing the advantages and disadvantages of traditional utility tunnel construction methods and development trend of prefabricated construction. The abovementioned method combines the advantages of prefabricated assembly technology in shield tunneling method with the cutandcover method, and transforms the traditional fixed support structure into a movable rigid support structure by corresponding equipment; and hence, the mechanization and standardization of the construction of utility tunnels are realized. The principle, applicable scope, process and operation keys of the Ushaped shield construction method are introduced. The force characteristics of Ushaped shield and traditional cutandcover support structure and their influences on the surrounding environment are compared; and the applicable scope of Ushaped shield and its advantages are analyzed. And then the test results of method in utility tunnel on Yehai Avenue in Haikou verify the superiority of the method in terms of schedule, economy and popularizing value. Finally, the applicable prospect of the method in the field of small curved radius, rectangular or Ushaped crosssection and the frame structure of cutandcover method is discussed, so as to provide a new design idea and construction method for the utility tunnel and similar projects in the future.

Key words: utility tunnel, Ushaped shield tunneling method, movable rigid support structure, prefabricated segment and assembly, mechanized construction